a). Field of the Invention
The present invention relates to suspension control system and method for a cab over type truck, viz., apparatus and method for controlling damping force characteristics of shock absorbers applicable to the cab over type truck.
b). Description of the Related Art
A Japanese Utility Model Registration Application (unexamined) Publication No. Heisei 7-37864 published on Jul. 14, 1995 exemplifies a first previously proposed suspension control system for a cab over type truck.
The first previously proposed suspension control system includes: damping force characteristic adjustable shock absorbers mounted at a cab part of the truck; a vehicle speed sensor arranged for detecting a running speed of the cab over truck; and a control unit arranged for controlling damping forces of the respective shock absorbers on the basis of the detected running speed value of the vehicle speed sensor.
Hence, during a relatively low running speed of the cab over type truck, a soft sense of feeling due to a low frequency input from a road surface can be suppressed from occurring in each of the shock absorbers and, during a relatively high running speed of the truck, a hard sense of feeling due to a high frequency input from the road surface can be suppressed from occurring in each of the shock absorber.
On the other hand, another Japanese Utility Model Registration Application Publication No. Heisei 5-26521 published on Apr. 6, 1993 exemplifies a second previously proposed suspension control system for the cab over type truck.
The second previously proposed suspension control system includes a damping force characteristic controller which carries out a suspension of a vehicle posture variation by temporarily enlarging the damping force of the vehicular shock absorbers during a vehicular braking on the basis of a signal derived from a vehicular motion state detector; a load weight detector. Then, the damping force characteristic controller is provided with damping force characteristic control maps to be selected on the basis of an output signal of the load weight sensor.
Hence, in such a vehicle that running characteristics are largely different depending upon whether the load weight is relatively light (no load weight) or is under a standard design, a suppression of a nose dib during the vehicular braking can be assured.